Wally626

Wally626

Joined on Oct 2, 2011

Comments

Total: 101, showing: 1 – 20
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In reply to:

toughluck: Apple goes to new lengths in greed here.
Normally, when you launch a new enterprise, you risk that it may fail and if it does, you're the only one to bear the brunt of it. But if you succeed, you're also the only one to benefit from it directly.
Apple is launching a new service, and what they planned to do was reap all the benefits of revenue while dropping the burden of cost on somebody else.
About those photographers' contracts: Don't you guys know how to shoot in bursts? Take 5-10 shots of the same scene, publish one picture, if there are interested buyers, sell the remaining 4-9. Technically, you're not breaking the contract. Or contact Swift's management to obtain a permission, like they're saying here.

Apple negotiated with the major labels to get three months free in exchange for a higher rate of return once the paid sales started. For established acts and labels it was a good deal but for new acts that may have big earnings for a short period of time, and that time was the three month trial, they would have been hurt.

Direct link | Posted on Jun 24, 2015 at 23:43 UTC
In reply to:

xeriwthe: wow serious innovation in sensor tech hitting the real time (sure, foveon's done it before but certainly not in a mainstream way). mad respect for sony's silicon engineering.

hope my favorite manufacturer can hold out long enough in today's insanely competitive camera business to bring their version to market!

The invention is not on the sensor side of the sensor. It is a normal back-side illuminated (BSI) sensor like Sony has been using in smaller cameras for a few years. The change is putting the memory on the back of the sensor chip so it can read out the pixel values much faster than a normal sensor can.

Direct link | Posted on Jun 11, 2015 at 13:50 UTC
On Alpha dog: Hands-on with Sony a7R II article (959 comments in total)
In reply to:

ptox: What's the downside to the electronic shutter? -- I assume there is one, or why would they bother with a mechanical shutter as well?

The e-shutter reads a line at a time, each line has a short exposure but by the time the camera is finished reading from top to bottom it could be 1/30th of a second, and thus a moving object gets distorted. The mechanical shutter normally goes much faster, say 1/250th or faster to cover the whole frame. Global shutter is the answer, reading the whole frame at one time into buffer cells then reading the cells out slowly. Not yet on this class of camera.

Direct link | Posted on Jun 10, 2015 at 19:39 UTC
On Alpha dog: Hands-on with Sony a7R II article (959 comments in total)
In reply to:

ptox: What's the downside to the electronic shutter? -- I assume there is one, or why would they bother with a mechanical shutter as well?

The drawback to EFCS is mostly that some lenses cannot stop down fast enough and you get a messed up exposure. Mostly a problem with larger aperture lenses shooting at small apertures. This is a problem on A-mount, never heard that it was a problem on E-mount at least with native lenses.

Direct link | Posted on Jun 10, 2015 at 19:29 UTC
In reply to:

raztec: Yup, this is the camera I want...but never in a million years will be able to afford.

I expect the Sony A7II plus 28mm f/2 is going to fall short of the results of this camera. Similar to the Sony RX1 being the best 35mm full frame camera. You lose versatility with the fixed lens design but it does allow the maker to have the best possible lens for the sensor, within its cost, size, mass envelope, without the restrictions due to the mount.

Direct link | Posted on Jun 10, 2015 at 15:28 UTC
On Massive $33,500 2450mm f/8 NASA lens surfaces on eBay article (235 comments in total)

First question is: what did the seller pay at the GSA auction for this item?

Direct link | Posted on Apr 29, 2015 at 12:57 UTC as 36th comment | 1 reply
On 3,200MP LSST camera gets construction approval article (257 comments in total)

These numbers may be a bit off, but I thought the equivalence folks would be interested. Based on a square sensor with 10 micron pixels the camera would have a diagonal of 800mm, with the reported 3.5° view angle that would be a focal length of 13,000 mm. With a 8.4m aperture that works out to f/1.6. In terms of a 35mm FF sensor that would be a 700mm lens. The crop factor of 18 would give you an aperture of 0.09 which is not possible. Using a f/5.6 lens you would need to push the ISO to 440,000. So a really big fast lens stuck on a Sony A7s pushed to ISO 400,000 would get you close except for resolution of course, only 12 MP versus 3.2 GP

Direct link | Posted on Feb 4, 2015 at 21:32 UTC as 7th comment
On Fujifilm announces XF 16-55mm F2.8 R LM WR lens article (295 comments in total)

I am a Sony guy, but it does look like a nice addition to the Fuji X-line. The size and cost is about the same as a Sony 16-50mm f/2.8 (A-mount) + LA-EA4 adaptor. A bit lighter and shorter plus not needing the complexity of an adaptor.

It really cannot be compared to the 24-70's of the world as those are built for a full frame sensor and that alone adds a lot of cost.

The closest E-mount lens is the Sony-Zeiss 16-70mm f/4. You gain a bit of focal length and lose a bit of speed for a little less money and a big drop in weight and size.

Seems the Fuji is pretty well positioned in comparison.

Direct link | Posted on Jan 6, 2015 at 14:52 UTC as 21st comment | 3 replies
In reply to:

Albino_BlacMan: How long of an exposure do you need at 0.005 lux. Isn't that an imperative piece of information?

I assume some of the better sensors out there can capture some kind of image at that level if you leave the shutter open long enough.

Reply to Nezhin
I am not sure on the requirements for how Gain is defined, some cameras do allow negative gains, but this might be like setting a camera to ISO 50 when the base ISO is 100. In practice it makes little difference as you will not be buying a camera with this sensor, unless it comes in your next car. If the same tech makes it into a still camera then the ISO value will be clear.

Direct link | Posted on Oct 22, 2014 at 22:32 UTC
In reply to:

Albino_BlacMan: How long of an exposure do you need at 0.005 lux. Isn't that an imperative piece of information?

I assume some of the better sensors out there can capture some kind of image at that level if you leave the shutter open long enough.

Reply to Nezhin
The exposure was 1/60th at f/1.4. We only know the exposure for the 0.005 lux scene was with 72 dB of gain, the same scene shot at 1/60 f/1.4 at 0 dB gain had 400 lux of light and was normally exposed. What we do not know is what ISO level 0 or 72 dB corresponds to. Although given the light is an intensity ratio there should be about 12 EV difference between the two exposures. I assumed 0 dB to be ISO 100 but of course it could be a different number, 200 or 400 or even 3200.

Direct link | Posted on Oct 22, 2014 at 13:31 UTC
In reply to:

Albino_BlacMan: How long of an exposure do you need at 0.005 lux. Isn't that an imperative piece of information?

I assume some of the better sensors out there can capture some kind of image at that level if you leave the shutter open long enough.

Reply to Nezhin, not sure how you get 270,000,000. If you are using decibels gain as used for power ratios. 72dB would equal 15,848,932 times, set to log 2 you get 23.92 EV, with a base ISO of 100 that would make it ISO 1,6 billion. If you use intensity ratio then 72 db is 3981.1, log2 is 11.96 EV or ISO 400,000 with base ISO of 100. Of course my db calculation memories are bit fuzzy

Direct link | Posted on Oct 21, 2014 at 16:52 UTC
In reply to:

Simple man: In the world of uneducated light engineers...... What exactly is a lux? And how does it compare to ISO?

Interesting design in my opinion. It's certainly small enough to be in a cellphone; should Sony decide to take it that route.

See http://en.wikipedia.org/wiki/Lux for a full explanation. In essences it is the amount of light illuminating an object.. Lux is a measure of the intensity of the light source (lumens) and the area over which it is spread.

ISO is the gain setting of the camera, with some adjustments to get it to meet the film standards. If you wish to use the same shutter speed and aperture to take an image you need to raise the ISO setting as the lux level falls. If you look at the example images in the story, Sony has an image shot at f/1.4 1/60th of a second exposure at 400 lux, at the cameras base ISO or 0db gain. They then reshot the image under 0.005 lux at 72db of gain. If the camera had a base ISO of 100 then the ISO used n the image would have been ISO400,000 but many video cameras use higher base ISO values, ISO 200, ISO 400 etc. which would increase the ISO level of the image. So it may have been ISO 800,000 or ISO 1,600,000

Direct link | Posted on Oct 21, 2014 at 16:45 UTC
On Zeiss launches Loxia full frame lenses for Sony E-mount article (268 comments in total)
In reply to:

donCortizone: Very nice. If I were into EVF's I'd seriously consider this system. (Assuming they roll out more than another set of 35/50's.)

Zeiss said they are coming out in order of basic popularity. These are based on the ZM line, a check of B&H on that line, list them in popularity as:
35mm f/2
50mm f/2
35mm f/2.8 (already covered by ZA lens
21mm f/2.8
50mm f/1.5
15mm f/2.8
25mm f/2.8
28mm f/2.8
85mm f/4
21mm f/4.5
18mm f/4
Pick 3 more after 50 and 35mm.

Direct link | Posted on Sep 2, 2014 at 20:07 UTC
On What is equivalence and why should I care? article (2131 comments in total)
In reply to:

Wally626: Equivalence in general works, but tends to break down on the margins. Yes a 50mm f/1.4 lens in a m4/3 camera at ISO 100 can get close to the same image as a 100mm f/2.8 on a FF camera at ISO 400, even more similar if both are 16 MP sensors. So same number of pixels, same DoF, roughly same noise level at both pixel and total image levels, same perspective, same shutter speed. However, this assumes a perfect lens, the m4/3 lens has to have a better resolution than the FF lens, or both have to be better than their sensors. It also falls apart if you stick a f/1.4 lens on the FF, what m4/3 is equivalent? Or your have a Nikon 800 with 36 MP, etc.

It is also easier to make a sharper lens for a smaller image circle which helps. Phone lenses are in general very sharp in terms of lines per mm, but of course have very few mm to work with.

Direct link | Posted on Jul 7, 2014 at 19:40 UTC
On What is equivalence and why should I care? article (2131 comments in total)

Equivalence in general works, but tends to break down on the margins. Yes a 50mm f/1.4 lens in a m4/3 camera at ISO 100 can get close to the same image as a 100mm f/2.8 on a FF camera at ISO 400, even more similar if both are 16 MP sensors. So same number of pixels, same DoF, roughly same noise level at both pixel and total image levels, same perspective, same shutter speed. However, this assumes a perfect lens, the m4/3 lens has to have a better resolution than the FF lens, or both have to be better than their sensors. It also falls apart if you stick a f/1.4 lens on the FF, what m4/3 is equivalent? Or your have a Nikon 800 with 36 MP, etc.

Direct link | Posted on Jul 7, 2014 at 16:03 UTC as 356th comment | 2 replies
On Surf's Up: Clark Little's incredible wave photography article (55 comments in total)

When a youth I went to Hawaii and me and a friend decide to body surf shore waves on Maui. When the big waves hit near the shore is was amazing, Standing in waist deep water, then bare sand, then crushed and spit up on the beach. Usually followed by the next wave whacking you in the head. Cudos for taking pictures in that type of surf.

Direct link | Posted on Jun 30, 2014 at 12:33 UTC as 14th comment
On Sony Alpha 7S added to test scene comparison tool article (272 comments in total)
In reply to:

Mike FL: FWIW:

Hopefully, this will start a new trend for all the manufactures to reduce the megapixels for sensors of all size for the sack of IQ.

The revolution of the A7s is not really in still images. It is a fine low light camera and will have very low per pixel noise compared to other cameras, but is not that much better or not better than the Nikon D4s and other FF bodies when the images are scaled to the same output. At low ISO the A7 or A7r would both be better as would many other cameras. Where the A7s is revolutionary is in the video. Being able to use all the pixels (at least from the 16:9 crop) gives the camera much more low light ability than any other camera available to consumers. It is not a difference of 10 or 20% it is several stops of difference.

Direct link | Posted on Jun 20, 2014 at 18:35 UTC
On Sigma 50mm F1.4 DG HSM | Art Lab Test Review preview (571 comments in total)
In reply to:

Frank_BR: I do not know why so much importance is given to distortion and vignetting, which can be easily corrected by software, provided they are not excessive.

It also seems a bit amateurish that a laboratory as DXO Labs can not discount the effect of the camera sensor on the test of a lens. Lenses that are tested today will continue to be sold for several years, but the DXO Labs results will be obsolete tomorrow because the sensors are continuously being improved.

There is a MTF value for the sensor by itself but I do not know of anyone who publishes it or measures it directly. The easiest method would be to measure the lens separately then measure the lens sensor combination then divide by they lens value. The combined value is just the product of the two separate measurements. So if the lens is 0.8 and the sensor is 0.95 (at a given frequency) then the overall value would be 0.76. I think in practice the sensor is near 1 for most of the frequencies used. A 24 MP sensor on FF has 4000 vertical pixels, so 167 pixels per mm, or 83 pixel pairs per mm. Depending on how one approaches the issues of sampling and such as well as issues such as antialiasing filters as well as sensor leakage you should end up with pretty good but not perfect resolution with samples of 40 line pairs per mm, which is normally the sharpest tested. With 2X oversampling the 24 MP FF is good to 42 lp/mm. A 36 MP sensor would get you 51 lp/mm.

Direct link | Posted on May 28, 2014 at 18:02 UTC
On Sony Cyber-shot DSC-RX100 III First Impressions Review preview (2962 comments in total)
In reply to:

Beckler8: This is more like a variation than an upgrade model. Video gets a big upgrade but audio, with no hot shoe and no mic input gets a huge downgrade. (Don't bother mentioning external recorders.) As the review points out, some will like the lens variation. Others, like me, would much prefer more/longer zoom range at the expense of lens speed. Not everyone wants maximum low-light performance at the expense of being able to do nothing zoom-wise...yes, 2.9x zoom is essentially nothing, esp. in video where presumably none of the smart digital zoom is usable. I'd gladly trade the flash for the hot shoe too! There must be a way to have both though. Anyway on a camera of this stature then, there needs to be 2 (or more) versions, catering to different preferences.

There are 3 versions of this camera, plus the RX10 if you really need the better video plus hot shoe plus clickable or non-clickable aperture and of course the 24-200mm equivalent f/2.8 lens.

Direct link | Posted on May 16, 2014 at 14:19 UTC
On Sony Cyber-shot DSC-RX100 III First Impressions Review preview (2962 comments in total)
In reply to:

discbrake: Good job, Sony. But OM-D E-M1 over RX100 III for a walk-around camera. E-M1 is "small" for me. I'm more excited for the Alpha 7s that will release in July.

The A6000 with 16-50mm kit lens has roughly the same equivalent aperture in terms of total light, DoF effects and focal length as the RX100mIII. Cost the same amount of money, but the A6000 is larger and heavier, not as good video quality and no built in ND filters. So larger more versatile camera if you buy extra lenses versus small compact camera. Seems to be a fair trade to me. My wife would prefer the RX100mIII and I the A6000.

Direct link | Posted on May 16, 2014 at 13:44 UTC
Total: 101, showing: 1 – 20
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